rb_f_notimplement must be used with arity -1
rb_f_notimplement must be used with arity -1

* Otherwise it fails to compile with:
  SPEC_CAPI_CXX=true mspec optional/capi/object_spec.rb

nobu/rubyspec,nobu/rubyspec,nobu/rubyspec,ruby/spec,ruby/spec,ruby/spec